(1) Field of the Invention
This invention relates to torpedoes and other such underwater vehicles and is directed more particularly to a tailcone assembly having means for attenuating vibrations of an underwater vehicle power drive assembly caused by thrust and depth forces acting upon the underwater vehicle power drive assembly.
(2) Description of the Prior Art
When an underwater vehicle, such as a torpedo, is underway, a thrust force is developed by the rotating propellers, and water pressure is exerted against the propellers. Torpedoes typically have been provided with radial and thrust bearings in the afterbody shell of the torpedo to support the drive shaft and to accommodate its associated forces. Such bearings cause the forces to be transferred into the tailcone shell whereupon the forces are passed forward along the torpedo hull. Transference of the forces along the torpedo hull excites the hull and causes vibratory energy resulting from the forces to radiate into the underwater environment, producing undesirable vibrations and noise. Accordingly, the tailcone often serves as an acoustical radiator, radiating noises into the surrounding underwater environment. Such vibrations and noises can contribute to detection of the torpedo or underwater vehicle and provide an opportunity for evasive action or countermeasures.
There is thus a need for attenuation of vibratory energy and acoustical energy in torpedo tailcones to facilitate quieter running to diminish chances of detection.